492 



SCIENCE. 



[N. S. Vol. XXIV. No. 616. 



establishment of this unique industry, not 

 only in having to invent a suitable plant, 

 but also to obtain even the raw material, 

 which was not then made of a definite 

 quality. The processes were quite different 

 in character from those in existing chemical 

 industries. The coloring matter also when 

 made was quite different from ordinary 

 dyes in its properties, and methods for its 

 application as a dye had to be discovered, 

 and this consumed much time. In fact, it 

 was all pioneering work. Nevertheless, the 

 mauve was supplied for silk dyeing as early 

 as December, 1857. 



I have mentioned these particulars be- 

 cause the production of this new color and 

 the practical proof of the possibility of 

 manufacturing it commercially was the 

 foundation of the coal tar color industry. 

 "When the mauve was seen to be a success, 

 of course every one commenced experiment- 

 ing with aniline, and three years after its 

 discovery magenta was discovered by M. 

 Verguin in France. None of the difficul- 

 ties I have mentioned were encountered in 

 the manufacture of this dye; the way was 

 clear and all the processes for the applica- 

 tion of the mauve were equally suitable for 

 the magenta, and, moreover, none of the 

 first prejudices in reference to such an 

 innovation as the mauve any longer existed. 



Other coloring matters were then discov- 

 ered by myself and in France by Messrs. 

 Girard and Delaire and then by Dr. Hof- 

 mann in England, many of which were 

 derivatives of magenta. These were pro- 

 duced not only in France but largely in 

 England by Messrs. Simpson, Maule and 

 Nicholson; they were also made to some 

 extent in Germany and Switzerland, and 

 very soon dyes of all the colors of the rain- 

 bow were obtained from commercial aniline, 

 and the industry made very rapid progress. 



In 1868 Graebe and Liebermann com- 

 menced an investigation on alizarine, the 

 natural coloring matter of the madder-root, 



from a purely scientific point of view ; this 

 led to the remarkable discovery that this 

 coloring matter is related to a coal-tar 

 product called anthracene, and they also 

 succeeded in producing it from this prod- 

 uct. This was the first natural coloring 

 matter which had been produced artifi- 

 cially. Their process, however, was not 

 suitable for the production of this coloring 

 matter technically. Having in my research 

 work studied anthracene and some of its 

 products, I endeavored to find a practical 

 process for the formation of alizarine, and 

 after a time succeeded in finding two suit- 

 able methods for its production on the 

 large scale. Caro, Graebe and Liebermann 

 quite independently also discovered one of 

 them. I and my brother then took up its 

 production at our works (my father having 

 died previously) , but many difficulties were 

 encountered, one being that of obtaining 

 anthracene, which was not then a commer- 

 cial product, but after visiting most of the 

 tar works in England and instructing the 

 tar distillers and agreeing to take what 

 they could make, a supply was soon ob- 

 tained in all different states of purity, 

 which quickly increased. In the meantime 

 the difficulties of the manufacture were 

 overcome and we were soon able to com- 

 mence supplying alizarine to the turkey- 

 red dyers. Our output rapidly increased, 

 and this artificial coloring matter has now 

 become one of the most important of the 

 coal tar colors and has superseded the nat- 

 ural dye, so that the cultivation of the 

 madder root has practically ceased. In 

 the year 1873 the demand for alizarine had 

 so increased that we felt that it would be 

 necessary to enlarge our works two or three 

 times to meet the demand. My brother 

 and I, however, did not care to undertake 

 this great responsibility ; we, therefore, sold 

 our works, hoping our successors would 

 follow up the matter. 



This ended my connection with the color 



